src/multiarray/_datetime.h File Reference

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Functions
NPY_NO_EXPORT void	numpy_pydatetime_import ()
NPY_NO_EXPORT int	is_leapyear (npy_int64 year)
NPY_NO_EXPORT npy_int64	get_datetimestruct_days (const npy_datetimestruct *dts)
NPY_NO_EXPORT PyArray_Descr *	create_datetime_dtype (int type_num, PyArray_DatetimeMetaData *meta)
NPY_NO_EXPORT PyArray_Descr *	create_datetime_dtype_with_unit (int type_num, NPY_DATETIMEUNIT unit)
NPY_NO_EXPORT PyArray_DatetimeMetaData *	get_datetime_metadata_from_dtype (PyArray_Descr *dtype)
NPY_NO_EXPORT PyArray_Descr *	datetime_type_promotion (PyArray_Descr *type1, PyArray_Descr *type2)
NPY_NO_EXPORT int	convert_datetimestruct_to_datetime (PyArray_DatetimeMetaData *meta, const npy_datetimestruct *dts, npy_datetime *out)
NPY_NO_EXPORT int	days_to_month_number (npy_datetime days)
NPY_NO_EXPORT int	parse_datetime_metadata_from_metastr (char *metastr, Py_ssize_t len, PyArray_DatetimeMetaData *out_meta)
NPY_NO_EXPORT PyArray_Descr *	parse_dtype_from_datetime_typestr (char *typestr, Py_ssize_t len)
NPY_NO_EXPORT NPY_DATETIMEUNIT	parse_datetime_unit_from_string (char *str, Py_ssize_t len, char *metastr)
NPY_NO_EXPORT int	convert_datetime_divisor_to_multiple (PyArray_DatetimeMetaData *meta, int den, char *metastr)
NPY_NO_EXPORT npy_bool	datetime_metadata_divides (PyArray_DatetimeMetaData *dividend, PyArray_DatetimeMetaData *divisor, int strict_with_nonlinear_units)
NPY_NO_EXPORT npy_bool	can_cast_datetime64_units (NPY_DATETIMEUNIT src_unit, NPY_DATETIMEUNIT dst_unit, NPY_CASTING casting)
NPY_NO_EXPORT npy_bool	can_cast_datetime64_metadata (PyArray_DatetimeMetaData *src_meta, PyArray_DatetimeMetaData *dst_meta, NPY_CASTING casting)
NPY_NO_EXPORT npy_bool	can_cast_timedelta64_units (NPY_DATETIMEUNIT src_unit, NPY_DATETIMEUNIT dst_unit, NPY_CASTING casting)
NPY_NO_EXPORT npy_bool	can_cast_timedelta64_metadata (PyArray_DatetimeMetaData *src_meta, PyArray_DatetimeMetaData *dst_meta, NPY_CASTING casting)
NPY_NO_EXPORT void	get_datetime_conversion_factor (PyArray_DatetimeMetaData *src_meta, PyArray_DatetimeMetaData *dst_meta, npy_int64 *out_num, npy_int64 *out_denom)
NPY_NO_EXPORT PyObject *	convert_datetime_metadata_to_tuple (PyArray_DatetimeMetaData *meta)
NPY_NO_EXPORT int	convert_datetime_metadata_tuple_to_datetime_metadata (PyObject *tuple, PyArray_DatetimeMetaData *out_meta)
NPY_NO_EXPORT int	get_tzoffset_from_pytzinfo (PyObject *timezone, npy_datetimestruct *dts)
NPY_NO_EXPORT int	convert_pyobject_to_datetime_metadata (PyObject *obj, PyArray_DatetimeMetaData *out_meta)
NPY_NO_EXPORT PyObject *	append_metastr_to_string (PyArray_DatetimeMetaData *meta, int skip_brackets, PyObject *ret)
NPY_NO_EXPORT int	convert_pydatetime_to_datetimestruct (PyObject *obj, npy_datetimestruct *out, NPY_DATETIMEUNIT *out_bestunit, int apply_tzinfo)
NPY_NO_EXPORT int	convert_pyobject_to_datetime (PyArray_DatetimeMetaData *meta, PyObject *obj, NPY_CASTING casting, npy_datetime *out)
NPY_NO_EXPORT int	convert_pyobject_to_timedelta (PyArray_DatetimeMetaData *meta, PyObject *obj, NPY_CASTING casting, npy_timedelta *out)
NPY_NO_EXPORT PyObject *	convert_datetime_to_pyobject (npy_datetime dt, PyArray_DatetimeMetaData *meta)
NPY_NO_EXPORT PyObject *	convert_timedelta_to_pyobject (npy_timedelta td, PyArray_DatetimeMetaData *meta)
NPY_NO_EXPORT int	convert_datetime_to_datetimestruct (PyArray_DatetimeMetaData *meta, npy_datetime dt, npy_datetimestruct *out)
NPY_NO_EXPORT void	add_seconds_to_datetimestruct (npy_datetimestruct *dts, int seconds)
NPY_NO_EXPORT void	add_minutes_to_datetimestruct (npy_datetimestruct *dts, int minutes)
NPY_NO_EXPORT npy_bool	has_equivalent_datetime_metadata (PyArray_Descr *type1, PyArray_Descr *type2)
NPY_NO_EXPORT int	cast_datetime_to_datetime (PyArray_DatetimeMetaData *src_meta, PyArray_DatetimeMetaData *dst_meta, npy_datetime src_dt, npy_datetime *dst_dt)
NPY_NO_EXPORT int	cast_timedelta_to_timedelta (PyArray_DatetimeMetaData *src_meta, PyArray_DatetimeMetaData *dst_meta, npy_timedelta src_dt, npy_timedelta *dst_dt)
NPY_NO_EXPORT npy_bool	is_any_numpy_datetime_or_timedelta (PyObject *obj)
NPY_NO_EXPORT PyArrayObject *	datetime_arange (PyObject *start, PyObject *stop, PyObject *step, PyArray_Descr *dtype)
NPY_NO_EXPORT PyArray_Descr *	find_object_datetime_type (PyObject *obj, int type_num)
Variables
NPY_NO_EXPORT char *	_datetime_strings [NPY_DATETIME_NUMUNITS]
NPY_NO_EXPORT int	_days_per_month_table [2][12]

---

Function Documentation

NPY_NO_EXPORT void add_minutes_to_datetimestruct	(	npy_datetimestruct *	dts,
		int	minutes
	)

Adjusts a datetimestruct based on a minutes offset. Assumes the current values are valid.

MINUTES

HOURS

DAYS

References PyArray_DatetimeMetaData::base, and NPY_FR_GENERIC.

NPY_NO_EXPORT void add_seconds_to_datetimestruct	(	npy_datetimestruct *	dts,
		int	seconds
	)

Adjusts a datetimestruct based on a seconds offset. Assumes the current values are valid.

NPY_NO_EXPORT PyObject* append_metastr_to_string	(	PyArray_DatetimeMetaData *	meta,
		int	skip_brackets,
		PyObject *	ret
	)

'ret' is a PyUString containing the datetime string, and this function appends the metadata string to it.

If 'skip_brackets' is true, skips the '[]'.

This function steals the reference 'ret'

Without brackets, give a string "generic"

But with brackets, append nothing

References convert_pydatetime_to_datetimestruct(), npy_datetimestruct::day, get_datetimestruct_minutes(), npy_datetimestruct::hour, npy_datetimestruct::min, npy_datetimestruct::month, and npy_datetimestruct::year.

Referenced by can_cast_timedelta64_units().

NPY_NO_EXPORT npy_bool can_cast_datetime64_metadata	(	PyArray_DatetimeMetaData *	src_meta,
		PyArray_DatetimeMetaData *	dst_meta,
		NPY_CASTING	casting
	)

This provides the casting rules for the DATETIME data type metadata.

References NPY_FR_D, NPY_FR_h, NPY_FR_M, NPY_FR_m, NPY_FR_W, and NPY_FR_Y.

NPY_NO_EXPORT npy_bool can_cast_datetime64_units	(	NPY_DATETIMEUNIT	src_unit,
		NPY_DATETIMEUNIT	dst_unit,
		NPY_CASTING	casting
	)

This provides the casting rules for the DATETIME data type units.

Notably, there is a barrier between 'date units' and 'time units' for all but 'unsafe' casting.

Allow anything with unsafe casting

Only enforce the 'date units' vs 'time units' barrier with 'same_kind' casting.

Enforce the 'date units' vs 'time units' barrier and that casting is only allowed towards more precise units with 'safe' casting.

Enforce equality with 'no' or 'equiv' casting

Referenced by parse_iso_8601_datetime().

NPY_NO_EXPORT npy_bool can_cast_timedelta64_metadata	(	PyArray_DatetimeMetaData *	src_meta,
		PyArray_DatetimeMetaData *	dst_meta,
		NPY_CASTING	casting
	)

This provides the casting rules for the TIMEDELTA data type metadata.

Referenced by PyArray_CanCastTo().

NPY_NO_EXPORT npy_bool can_cast_timedelta64_units	(	NPY_DATETIMEUNIT	src_unit,
		NPY_DATETIMEUNIT	dst_unit,
		NPY_CASTING	casting
	)

This provides the casting rules for the TIMEDELTA data type units.

Notably, there is a barrier between the nonlinear years and months units, and all the other units.

Allow anything with unsafe casting

Only enforce the 'date units' vs 'time units' barrier with 'same_kind' casting.

Enforce the 'date units' vs 'time units' barrier and that casting is only allowed towards more precise units with 'safe' casting.

Enforce equality with 'no' or 'equiv' casting

References append_metastr_to_string(), PyUString_ConcatAndDel, and PyUString_FromString.

NPY_NO_EXPORT int cast_datetime_to_datetime	(	PyArray_DatetimeMetaData *	src_meta,
		PyArray_DatetimeMetaData *	dst_meta,
		npy_datetime	src_dt,
		npy_datetime *	dst_dt
	)

Casts a single datetime from having src_meta metadata into dst_meta metadata.

Returns 0 on success, -1 on failure.

If the metadata is the same, short-circuit the conversion

Otherwise convert through a datetimestruct

References compute_datetime_metadata_greatest_common_divisor(), find_string_array_datetime64_type(), get_datetime_metadata_from_dtype(), NPY_DATETIME, NPY_OBJECT, NPY_STRING, NPY_TIMEDELTA, NPY_UNICODE, PyArray_Check, PyArray_DESCR, PyArray_IsScalar, and _PyArray_Descr::type_num.

NPY_NO_EXPORT int cast_timedelta_to_timedelta	(	PyArray_DatetimeMetaData *	src_meta,
		PyArray_DatetimeMetaData *	dst_meta,
		npy_timedelta	src_dt,
		npy_timedelta *	dst_dt
	)

Casts a single timedelta from having src_meta metadata into dst_meta metadata.

Returns 0 on success, -1 on failure.

If the metadata is the same, short-circuit the conversion

Get the conversion factor

Apply the scaling

NPY_NO_EXPORT int convert_datetime_divisor_to_multiple	(	PyArray_DatetimeMetaData *	meta,
		int	den,
		char *	metastr
	)

Translate divisors into multiples of smaller units. 'metastr' is used for the error message if the divisor doesn't work, and can be NULL if the metadata didn't come from a string.

Returns 0 on success, -1 on failure.

Translate divisors into multiples of smaller units. 'metastr' is used for the error message if the divisor doesn't work, and can be NULL if the metadata didn't come from a string.

This function only affects the 'base' and 'num' values in the metadata.

Returns 0 on success, -1 on failure.

NPY_NO_EXPORT PyObject* convert_datetime_metadata_to_tuple

(

PyArray_DatetimeMetaData *

meta

)

Given a pointer to datetime metadata, returns a tuple for pickling and other purposes.

NPY_NO_EXPORT int convert_datetime_metadata_tuple_to_datetime_metadata	(	PyObject *	tuple,
		PyArray_DatetimeMetaData *	out_meta
	)

Converts a metadata tuple into a datetime metadata C struct.

Returns 0 on success, -1 on failure.

Allow unicode format strings: convert to bytes

Convert the values to longs

NPY_NO_EXPORT int convert_datetime_to_datetimestruct	(	PyArray_DatetimeMetaData *	meta,
		npy_datetime	dt,
		npy_datetimestruct *	out
	)

Converts a datetime based on the given metadata into a datetimestruct

Initialize the output to all zeros

NaT is signaled in the year

Datetimes can't be in generic units

TODO: Change to a mechanism that avoids the potential overflow

Note that care must be taken with the / and % operators for negative values.

A week is 7 days

entire range is only +- 2.6 hours

Offset the negative minutes

entire range is only +- 9.2 seconds

Offset the negative seconds

NPY_NO_EXPORT PyObject* convert_datetime_to_pyobject	(	npy_datetime	dt,
		PyArray_DatetimeMetaData *	meta
	)

Converts a datetime into a PyObject *.

System Message: WARNING/2 (<string>, line 1); backlink Inline emphasis start-string without end-string.

For days or coarser, returns a datetime.date. For microseconds or coarser, returns a datetime.datetime. For units finer than microseconds, returns an integer.

Converts a datetime into a PyObject *.

System Message: WARNING/2 (<string>, line 1); backlink Inline emphasis start-string without end-string.

Not-a-time is returned as the string "NaT". For days or coarser, returns a datetime.date. For microseconds or coarser, returns a datetime.datetime. For units finer than microseconds, returns an integer.

Convert NaT (not-a-time) and any value with generic units into None.

If the type's precision is greater than microseconds, return an int

Convert to a datetimestruct

If the year is outside the range of years supported by Python's datetime, or the datetime64 falls on a leap second, return a raw int.

If the type's precision is greater than days, return a datetime

Otherwise return a date

NPY_NO_EXPORT int convert_datetimestruct_to_datetime	(	PyArray_DatetimeMetaData *	meta,
		const npy_datetimestruct *	dts,
		npy_datetime *	out
	)

Converts a datetime from a datetimestruct to a datetime based on some metadata.

Converts a datetime from a datetimestruct to a datetime based on some metadata. The date is assumed to be valid.

TODO: If meta->num is really big, there could be overflow

Returns 0 on success, -1 on failure.

If the datetimestruct is NaT, return NaT

Cannot instantiate a datetime with generic units

Truncate to the year

Truncate to the month

Otherwise calculate the number of days to start

Truncate to weeks

only 2.6 hours

only 9.2 secs

Something got corrupted

Divide by the multiplier

Referenced by _strided_to_strided_datetime_general_cast(), and convert_pydatetime_to_datetimestruct().

NPY_NO_EXPORT int convert_pydatetime_to_datetimestruct	(	PyObject *	obj,
		npy_datetimestruct *	out,
		NPY_DATETIMEUNIT *	out_bestunit,
		int	apply_tzinfo
	)

Tests for and converts a Python datetime.datetime or datetime.date object into a NumPy npy_datetimestruct.

'out_bestunit' gives a suggested unit based on whether the object

was a datetime.date or datetime.datetime object.

If 'apply_tzinfo' is 1, this function uses the tzinfo to convert to UTC time, otherwise it returns the struct with the local time.

Returns -1 on error, 0 on success, and 1 (with no error set) if obj doesn't have the neeeded date or datetime attributes.

Tests for and converts a Python datetime.datetime or datetime.date object into a NumPy npy_datetimestruct.

While the C API has PyDate_* and PyDateTime_* functions, the following implementation just asks for attributes, and thus supports datetime duck typing. The tzinfo time zone conversion would require this style of access anyway.

'out_bestunit' gives a suggested unit based on whether the object

was a datetime.date or datetime.datetime object.

If 'apply_tzinfo' is 1, this function uses the tzinfo to convert to UTC time, otherwise it returns the struct with the local time.

Returns -1 on error, 0 on success, and 1 (with no error set) if obj doesn't have the neeeded date or datetime attributes.

Initialize the output to all zeros

Need at least year/month/day attributes

Get the year

Get the month

Get the day

Validate that the month and day are valid for the year

Check for time attributes (if not there, return success as a date)

The best unit for date is 'D'

Get the hour

Get the minute

Get the second

Get the microsecond

Apply the time zone offset if it exists

The utcoffset function should return a timedelta

The timedelta should have a function "total_seconds" which contains the value we want.

Convert to a minutes offset and apply it

The resolution of Python's datetime is 'us'

References PyArray_DatetimeMetaData::base, convert_datetimestruct_to_datetime(), convert_pydatetime_to_datetimestruct(), NPY_FR_D, PyArray_DatetimeMetaData::num, and raise_if_datetime64_metadata_cast_error().

Referenced by append_metastr_to_string(), and convert_pydatetime_to_datetimestruct().

NPY_NO_EXPORT int convert_pyobject_to_datetime	(	PyArray_DatetimeMetaData *	meta,
		PyObject *	obj,
		NPY_CASTING	casting,
		npy_datetime *	out
	)

Converts a PyObject * into a datetime, in any of the forms supported.

If the units metadata isn't known ahead of time, set meta->base to -1, and this function will populate meta with either default values or values from the input object.

The 'casting' parameter is used to control what kinds of inputs are accepted, and what happens. For example, with 'unsafe' casting, unrecognized inputs are converted to 'NaT' instead of throwing an error, while with 'safe' casting an error will be thrown if any precision from the input will be thrown away.

Returns -1 on error, 0 on success.

Convert to an ASCII string for the date parser

Parse the ISO date

Use the detected unit if none was specified

Do no conversion on raw integers

Don't allow conversion from an integer without specifying a unit

Datetime scalar

Copy the scalar directly if units weren't specified

Otherwise do a casting transformation

Allow NaT (not-a-time) values to slip through any rule

Datetime zero-dimensional array

Copy the value directly if units weren't specified

Otherwise do a casting transformation

Allow NaT (not-a-time) values to slip through any rule

Convert from a Python date or datetime object

Use the detected unit if none was specified

With unsafe casting, convert unrecognized objects into NaT and with same_kind casting, convert None into NaT

NPY_NO_EXPORT int convert_pyobject_to_datetime_metadata	(	PyObject *	obj,
		PyArray_DatetimeMetaData *	out_meta
	)

Converts an input object into datetime metadata. The input may be either a string or a tuple.

Returns 0 on success, -1 on failure.

Get an ASCII string

Allow unicode format strings: convert to bytes

NPY_NO_EXPORT int convert_pyobject_to_timedelta	(	PyArray_DatetimeMetaData *	meta,
		PyObject *	obj,
		NPY_CASTING	casting,
		npy_timedelta *	out
	)

Converts a PyObject * into a timedelta, in any of the forms supported

If the units metadata isn't known ahead of time, set meta->base to -1, and this function will populate meta with either default values or values from the input object.

The 'casting' parameter is used to control what kinds of inputs are accepted, and what happens. For example, with 'unsafe' casting, unrecognized inputs are converted to 'NaT' instead of throwing an error, while with 'safe' casting an error will be thrown if any precision from the input will be thrown away.

Returns -1 on error, 0 on success.

Convert to an ASCII string for the date parser

Check for a NaT string

Parse as an integer

Use generic units if none was specified

Do no conversion on raw integers

Use the default unit if none was specified

Timedelta scalar

Copy the scalar directly if units weren't specified

Otherwise do a casting transformation

Allow NaT (not-a-time) values to slip through any rule

Timedelta zero-dimensional array

Copy the value directly if units weren't specified

Otherwise do a casting transformation

Allow NaT (not-a-time) values to slip through any rule

Convert from a Python timedelta object

Get the days

Get the seconds

Get the microseconds

Use microseconds if none was specified

Detect the largest unit where every value after is zero, to allow safe casting to seconds if microseconds is zero, for instance.

Switch back to microseconds for the casting operation

With unsafe casting, convert unrecognized objects into NaT and with same_kind casting, convert None into NaT

NPY_NO_EXPORT PyObject* convert_timedelta_to_pyobject	(	npy_timedelta	td,
		PyArray_DatetimeMetaData *	meta
	)

Converts a timedelta into a PyObject *.

System Message: WARNING/2 (<string>, line 1); backlink Inline emphasis start-string without end-string.

Not-a-time is returned as the string "NaT". For microseconds or coarser, returns a datetime.timedelta. For units finer than microseconds, returns an integer.

Convert NaT (not-a-time) into None.

If the type's precision is greater than microseconds, is Y/M/B (nonlinear units), or is generic units, return an int

Apply the unit multiplier (TODO: overflow treatment...)

Convert to days/seconds/useconds

'value' represents days, and seconds/useconds are filled.

If it would overflow the datetime.timedelta days, return a raw int

NPY_NO_EXPORT PyArray_Descr* create_datetime_dtype	(	int	type_num,
		PyArray_DatetimeMetaData *	meta
	)

Creates a datetime or timedelta dtype using a copy of the provided metadata.

Create a default datetime or timedelta

Copy the metadata

Referenced by apply_business_day_count(), and business_day_offset().

NPY_NO_EXPORT PyArray_Descr* create_datetime_dtype_with_unit	(	int	type_num,
		NPY_DATETIMEUNIT	unit
	)

Creates a datetime or timedelta dtype using the given unit.

NPY_NO_EXPORT PyArrayObject* datetime_arange	(	PyObject *	start,
		PyObject *	stop,
		PyObject *	step,
		PyArray_Descr *	dtype
	)

Implements a datetime-specific arange

Both datetime and timedelta are stored as int64, so they can share value variables.

First normalize the input parameters so there is no Py_None, and start is moved to stop if stop is unspecified.

If start was NULL or None, raise an exception

Step must not be a Datetime

Check if the units of the given dtype are generic, in which case we use the code path that detects the units

If the dtype specified is in generic units, detect the units from the input parameters.

Otherwise use the provided metadata

Set up to convert the objects to a common datetime unit metadata

Convert all the arguments

If no step was provided, default to 1

In the case of arange(datetime, timedelta), convert the timedelta into a datetime by adding the start datetime.

Now start, stop, and step have their values and matching metadata

Calculate the array length

Create the dtype of the result

Create the result array

Extract the data pointer

Create the timedeltas or datetimes

NPY_NO_EXPORT npy_bool datetime_metadata_divides	(	PyArray_DatetimeMetaData *	dividend,
		PyArray_DatetimeMetaData *	divisor,
		int	strict_with_nonlinear_units
	)

Determines whether the 'divisor' metadata divides evenly into the 'dividend' metadata.

Generic units divide into anything

Non-generic units never divide into generic units

If the bases are different, factor in a conversion

Years and Months are incompatible with all other units (except years and months are compatible with each other).

Could do something complicated here

Could do something complicated here

Could do something complicated here

Take the greater base (unit sizes are decreasing in enum)

Crude, incomplete check for overflow

NPY_NO_EXPORT PyArray_Descr* datetime_type_promotion	(	PyArray_Descr *	type1,
		PyArray_Descr *	type2
	)

Both type1 and type2 must be either NPY_DATETIME or NPY_TIMEDELTA. Applies the type promotion rules between the two types, returning the promoted type.

Create a DATETIME or TIMEDELTA dtype

Get the metadata GCD, being strict about nonlinear units for timedelta and relaxed for datetime.

References npy_datetimestruct::sec.

NPY_NO_EXPORT int days_to_month_number

(

npy_datetime

days

)

Extracts the month number, within the current year, from a 'datetime64[D]' value. January is 1, etc.

Extracts the month number from a 'datetime64[D]' value

Should never get here

NPY_NO_EXPORT PyArray_Descr* find_object_datetime_type	(	PyObject *	obj,
		int	type_num
	)

Examines all the objects in the given Python object by recursively descending the sequence structure. Returns a datetime or timedelta type with metadata based on the data.

NPY_NO_EXPORT void get_datetime_conversion_factor	(	PyArray_DatetimeMetaData *	src_meta,
		PyArray_DatetimeMetaData *	dst_meta,
		npy_int64 *	out_num,
		npy_int64 *	out_denom
	)

Computes the conversion factor to convert data with 'src_meta' metadata into data with 'dst_meta' metadata.

If overflow occurs, both out_num and out_denom are set to 0, but no error is set.

Generic units change to the destination with no conversion factor

Converting to a generic unit from something other than a generic unit is an error.

Conversions between years/months and other units use the factor averaged over the 400 year leap year cycle.

Year -> Day

Day -> dst_base

Month -> Day

Day -> dst_base

If something overflowed, make both num and denom 0

Swap the numerator and denominator if necessary

Return as a fraction in reduced form

NPY_NO_EXPORT PyArray_DatetimeMetaData* get_datetime_metadata_from_dtype

(

PyArray_Descr *

dtype

)

This function returns a pointer to the DateTimeMetaData contained within the provided datetime dtype.

Referenced by cast_datetime_to_datetime(), and PyArray_CanCastTo().

NPY_NO_EXPORT npy_int64 get_datetimestruct_days

(

const npy_datetimestruct *

dts

)

Calculates the days offset from the 1970 epoch.

Adjust for leap years

1968 is the closest leap year before 1970. Exclude the current year, so add 1.

Add one day for each 4 years

1900 is the closest previous year divisible by 100

Subtract one day for each 100 years

1600 is the closest previous year divisible by 400

Add one day for each 400 years

1972 is the closest later year after 1970. Include the current year, so subtract 2.

Subtract one day for each 4 years

2000 is the closest later year divisible by 100

Add one day for each 100 years

2000 is also the closest later year divisible by 400

Subtract one day for each 400 years

Add the months

Add the days

NPY_NO_EXPORT int get_tzoffset_from_pytzinfo	(	PyObject *	timezone_obj,
		npy_datetimestruct *	dts
	)

Gets a tzoffset in minutes by calling the fromutc() function on the Python datetime.tzinfo object.

Create a Python datetime to give to the timezone object

Convert the datetime from UTC to local time

Convert the local datetime into a datetimestruct

Calculate the tzoffset as the difference between the datetimes

NPY_NO_EXPORT npy_bool has_equivalent_datetime_metadata	(	PyArray_Descr *	type1,
		PyArray_Descr *	type2
	)

Returns true if the datetime metadata matches

For generic units, the num is ignored

Referenced by PyArray_Correlate().

NPY_NO_EXPORT npy_bool is_any_numpy_datetime_or_timedelta

(

PyObject *

obj

)

Returns true if the object is something that is best considered a Datetime or Timedelta, false otherwise.

NPY_NO_EXPORT int is_leapyear

(

npy_int64

year

)

Returns 1 if the given year is a leap year, 0 otherwise.

<

year % 4 == 0

References npy_datetimestruct::year.

Referenced by days_to_yearsdays(), and get_datetimestruct_minutes().

NPY_NO_EXPORT void numpy_pydatetime_import

(

void

)

Imports the PyDateTime functions so we can create these objects. This is called during module initialization

NPY_NO_EXPORT int parse_datetime_metadata_from_metastr	(	char *	metastr,
		Py_ssize_t	len,
		PyArray_DatetimeMetaData *	out_meta
	)

Parses the metadata string into the metadata C structure.

Returns 0 on success, -1 on failure.

Treat the empty string as generic units

The metadata string must start with a '['

Parse the extended unit inside the []

NPY_NO_EXPORT NPY_DATETIMEUNIT parse_datetime_unit_from_string	(	char *	str,
		Py_ssize_t	len,
		char *	metastr
	)

Converts a substring given by 'str' and 'len' into a date time unit enum value. The 'metastr' parameter is used for error messages, and may be NULL.

Returns 0 on success, -1 on failure.

Converts a substring given by 'str' and 'len' into a date time unit enum value. The 'metastr' parameter is used for error messages, and may be NULL.

Generic units have no representation as a string in this form.

Returns 0 on success, -1 on failure.

Use switch statements so the compiler can make it fast

All the two-letter units are variants of seconds

If nothing matched, it's an error

References npy_datetimestruct::month, and npy_datetimestruct::year.

NPY_NO_EXPORT PyArray_Descr* parse_dtype_from_datetime_typestr	(	char *	typestr,
		Py_ssize_t	len
	)

Converts a datetype dtype string into a dtype descr object. The "type" string should be NULL-terminated, and len should contain its string length.

Converts a datetype dtype string into a dtype descr object. The "type" string should be NULL-terminated.

First validate that the root is correct, and get the metadata string address

Parse the metadata string into a metadata struct

---

Variable Documentation

NPY_NO_EXPORT char* _datetime_strings[NPY_DATETIME_NUMUNITS]

Referenced by parse_iso_8601_datetime().

NPY_NO_EXPORT int _days_per_month_table[2][12]

Referenced by days_to_yearsdays(), and get_datetimestruct_minutes().